The invention relates generally to passenger ride discomfort and more specifically concerns a tool for estimating passenger ride discomfort within complex ride environments.
The prior art methods and devices for measuring passenger ride discomfort generally measure and display individual vertical or lateral accelerations that are frequency weighted according to ride comfort curves derived from motion sickness data and the International Standards Organization recommendations. These devices and methods output a weighted value of acceleration for either of the two axes of motion. The resultant weighted acceleration level is usually interpreted in a dichotomous manner, i.e., representing a ride that is comfortable or uncomfortable.
The disadvantages of the prior art include the following. The output of existing devices and methods is a frequency weighted value of physical acceleration which does not necessarily relate on a one-to-one basis with the associated subjective experience of the measured environment. For example, many different vibrations (which produce large variations in subjective discomfort) can have identical weighted acceleration levels. Thus, a weighted output of these devices and methods does not generally represent a single unique level of subjective discomfort/acceptance. Existing devices and methods are limited to the production of comfort indices for single axes of vibration. They cannot provide reliable estimates of discomfort due to simultaneous vibrations in more than one axis of vibration. They canot adequately assess the effect upon subjective discomfort of multiple frequencies of vibration within individual axes; they do not account for the interaction and/or summation of the effects of combined noise and fibration upon human discomfort/acceptance; they do not incorporate the effects of angular vibrations, either singly or in combination with linear vibrations; and they do not account for adaptation of passengers to the vibration environment.
It is an object of this invention to provide a ride quality meter in which simultaneous measurements of interior noise and vibrations in the transportation system are used.
Another object of this invention is to utilize the combined noise and vibration measurements, together with empirically derived psychophysical laws governing human discomfort response to combined noise and vibration to generate and display, in real time, an index of passenger discomfort that directly relates to passenger subjective acceptance of the measured ride environment.
A further object of this invention is to display at the option of the user, the contribution of the various components of the ride environment to the total discomfort experienced by passengers.
Still another object of this invention is to provide a ride quality meter in which the effects of multiple frequencies and multiple axes of vibration are automatically accounted for within the meter.
Other objects of this invention will become apparent hereinafter in the specification and drawings.